Before the Pilgrims landed on Plymouth Rock in 1620, the Calvinist group spent about ten years in the Dutch town of Leiden. You probably don't know much about what happened to them there. Historian Jeremy Dupertuis Bangs spent years piecing the story together, and has documented his findings in a new book. Meanwhile, you can taker a photographic tour of Leiden and the places that the Pilgrims lived, worked, met, and worshiped, at Smithsonian. Shown here is the Church of St. Louis, which served as a guildhall during the time of the Pilgrims. Link